反应详情

Acetic acid (8 ml) and zinc powder (6 g) were added under stirring and ice-cooling to a solution of 2,2,2-trichloroethyl 2-methyl-7-(3-phenylureido)-3-cephem-4-carboxylate (4.1 g) in anhydrous dimethylformamide (30 ml), and the mixture was stirred for 1 hour under ice-cooling and then 3.5 hours at room temperature. After the reaction 10% hydrochloric acid and ethyl acetate were added to the reaction mixture. The insoluble material was filtered off and the ethyl acetate layer was separated, and then extracted with a sodium bicarbonate aqueous solution. The extract was acidified with 10% hydrochloric acid and extracted with ethyl acetate, after which the extract was dried over magnesium sulfate. After the solvent was distilled off, the residue was crystallized by adding ether to give 2-methyl-7-(3-phenylureido)-3-cephem-4-carboxylic acid (1.0 g), mp 148° to 151° C.

1. stirringthe mixture was stirred for 1 hour under ice-
2. temperaturecooling
3. custom3.5 hours
4. customat room temperature
5. additionwere added to the reaction mixture
6. filtrationThe insoluble material was filtered off
7. customthe ethyl acetate layer was separated
8. extractionextracted with a sodium bicarbonate aqueous solution
9. extractionextracted with ethyl acetate
10. dry with materialafter which the extract was dried over magnesium sulfate
11. distillationAfter the solvent was distilled off
12. customthe residue was crystallized
13. additionby adding ether